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Nataly_w [17]
3 years ago
9

I dont understamd this problem please help------!

Mathematics
1 answer:
UkoKoshka [18]3 years ago
4 0
Hello,

Let's D_1\ the \ outflow\ of\ the\ new\ pump\\
D_2\ the \ outflow\ of\ the\ old\ pump\\\\
V \ the\ volume \of\ the\ tank\\\\

D_1*5=V==\ \textgreater \ D_1= \dfrac{V}{5} \\

D_2*7=V==\ \textgreater \ D_2= \dfrac{V}{7} \\

D_1+D_2= \dfrac{V}{5}+ \dfrac{V}{7} \\

D_1+D_2= \dfrac{7*V}{35}+ \dfrac{5*V}{35} \\

D_1+D_2= \dfrac{12V}{35} \\

Time \ for \ the \2 \pumps=V=(D_1+D_2)*\dfrac{35}{12}==>2H55min
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Loretta grew 54 watermelons in her garden last year. This year, that number increased by 5/9. Which expression shows the number
Mars2501 [29]

Answer:

54+\frac{5}{9}\times 54

Step-by-step explanation:

We are given that

Loretta grew  watermelons in her garden last year=54

We have to find the expression which shows the number of watermelons Loretta grew this year.

To find the expression which shows the  number of watermelons Loretta grew this year by adding watermelons grew in her garden last year and number of watermelons increased .

According to question

5/9 of 54=\frac{5}{9}\times 54

Therefore, the expression which shows the  number of watermelons Loretta grew this year

=54+\frac{5}{9}\times 54

6 0
3 years ago
A map has a scale of 3 cm and 20 cm which statement is true or false two cities are actually 66 cm part are9.9 cm part
victus00 [196]
Answer:
Answer options
A. Two cities that are 7.5 cm apart on the map are actually 50 km apart.
D. Two cities that are actually 66 km apart are 9.9 cm apart on the map.
Step-by-step explanation:
Step 1
Indicate the scale as shown;
3 cm : 20 km, meaning 3 cm on the map represents 20 km on the ground
A). what does 7.5 cm represent on the ground
Distance on ground=(7.5×20)/3=50 km
B). what does 4 cm represent on the ground
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C). what does 45 km on ground represent on the map
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D). what does 66 km on ground represent on the map
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3 years ago
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shepuryov [24]

Answer:

Step-by-step explanation:

\alpha+\beta=\dfrac{5}{2} \\\\\alpha*\beta=\dfrac{1}{2} \\\\\alpha^2+\beta^2=\dfrac{21}{4} \ (see\ previous\ post)\\\\(\alpha+\beta)^4=\dfrac{625}{16} \\\\=\alpha^4+\beta^4+4*\alpha^3*\beta+6*\alpha^2*\beta^2+4*\alpha*\beta^3\\\\=\alpha^4+\beta^4+4*(\alpha*\beta)(\alpha^2+\beta^2)+6*\alpha^2*\beta^2\\\\\alpha^4+\beta^4=(\alpha+\beta)^4-4*(\alpha*\beta)(\alpha^2+\beta^2)-6*\alpha^2*\beta^2\\\\= \dfrac{625}{16} -4*\dfrac{1}{2} *\dfrac{21}{4} -6*(\dfrac{1}{2})^2 \\\\

= \dfrac{625}{16}- \dfrac{168}{16}-\dfrac{24}{16}\\\\\\= \dfrac{433}{16}

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